ORANJESTAD, Aruba (CNN) -- A search near an Aruba beachfront hotel that began in the afternoon ended Tuesday night with apparently no sign of 18-year-old Natalee Holloway, the Alabama student missing since May 30.

Investigators late Tuesday took down barricades and cordons that had been up for five and a half hours while searchers combed the area.

A source close to the probe said search participants included five FBI agents and a search dog from Miami-Dade County, Florida, in addition to Aruban police.

The area -- about 500 yards long and 150 yards wide -- contains mangroves, scrub brush and drainage ditches.

A fire truck brought in a pump that was used to drain parts of the property, which is sandwiched between the main highway that goes around the coast and the beach area next to the Marriott Hotel.

The area is known as a "lover's lane" for romantic couples.

Three young men are in jail and have been undergoing questioning. They were the last people reported seen with Holloway. None has been formally charged.

Police have identified them as brothers Satish Kalpoe, 18, and Depak Kalpoe, 21, and their friend, Joran Van Der Sloot, 17, the son of an Aruban judge.

"The boys continue to point fingers at each other," the source said, but their attorneys said their clients are innocent.

"My client is maintaining that he is innocent and that he did not commit any crime," said Antonio Carlo, the attorney for Van Der Sloot.

Aruba government spokesman Ruben Trapenberg said he didn't know what prompted Tuesday's search.

"People have gone over the area [before] but not as intensely as this time," Trapenberg said, adding that every part of the island was being checked.

He said Aruba requested and had received additional technical assistance from Dutch and U.S. authorities, but didn't elaborate.

Holloway, from the Birmingham suburb of Mountain Brook, has been missing more than two weeks. She was on a trip to Aruba with classmates and parent chaperones to celebrate her high school graduation.

The Kalpoes and Ver Der Sloot reportedly told police they took Holloway to a beach after leaving an Oranjestad nightclub with her early May 30. They said they returned her to her hotel, the Holiday Inn, not long afterward.

On Monday, authorities released two security guards arrested in connection with her disappearance.

Abraham Jones, 28, and Mickey John, 30, who work at a hotel near where the teen was staying, were arrested in the case June 5 but were never charged.

After his release, John said Depak Kalpoe confided to him while they were in jail together that he had lied to police. John said Kalpoe also apologized for getting Jones and him into "that mess." (CNN Access)

"He [Depak] told me that the story about dropping the girl off at the Holiday Inn was all made up," John said, adding that Kalpoe told him he and his brother dropped Van Der Sloot and Holloway off near a Marriott hotel and then went home.

The area searched Tuesday is near the Marriott, about a mile from the Holiday Inn where Holloway was staying.

John said Kalpoe told him the brothers figured Holloway would turn up "a few days after, in some crack house or beach bar."

He said Tuesday that Kalpoe should be more forthright with investigators.

The source close to the probe said the FBI has been briefing Holloway's parents in Aruba, and Holloway's mother said Tuesday she believes the investigation is moving forward.

"I feel like that we are working in a collaborative effort," Beth Holloway Twitty told CNN's "American Morning."

"From the family to the FBI to the local authorities to the Aruban government to the U.S. government, I feel like we are all in this investigation, and I do feel like we are beginning to proceed forward. ... That's where I want to go because that will help us find our daughter."

Twitty and her husband remain in Aruba, vowing not to leave the Caribbean island off Venezuela without Holloway.

"Some days, they are agonizing," Twitty said. "They are so difficult. And some days, I have the deepest hurt that anyone could ever imagine."

She said she wasn't aware of John's allegations that one of the three in custody told him he had lied to police.

"The best thing that we have to do is to allow the proper authorities now to do their investigation," Twitty said. "This is their expertise, and I feel the assurance and trust that we are moving in the right direction."

Aruban Prime Minister Nelson Oduber has said his government "is doing the utmost" to find Holloway.

"We hope that we will find Natalee Holloway alive and are still praying that there is nothing bad that has happened to her," Oduber said Sunday.

While expressing concern about Holloway, Oduber also sought to reassure the media that the island is safe for visitors, noting that more than 60 percent of its income comes from tourism and more than 45,000 Arubans work in that industry.

"That's why we make an appeal to our local press and international press that the government and everybody involved will do the job," he said.